Dobby finger for looms



Nov. 1, 1938. AE. R. HOLMES DOBBY FINGER FOR LOOMS Filed Deo. 2l, 1936 www . dobby lingers are commonly provided Vjacent dobby lingers, Y which Patented Nov. 1, 1938 ENT ori-ICE BOBBY FINGER vFOR. LQOMS ElbridgeR. Holmes,

Worcester, Mass., assignor to Crompton & Knowles Loom Works, Worcester, Mass., a corporation of Massachusetts Application December 21, 193e, serial No. 116,974

1 Claim.

This invention relates to dobbies used for selectin-g and shifting loom harnesses, and relates moreparticularlylto thedobby lingers forming a usual part of such mechanisms. Two such for each loom harness, and these dobby lingers are mounted in closely parallel relation and with relatively slight clearance between adjacent lingers.

Difficulty is at times encountered by reason of the accumulation of lint and dirt between adaccumulations may cause two adjacent fingers to be raised, due to friction between the lingers, when the raising of one linger only is indicated by the pattern chain. Such inadvertent lifting of a second dobby linger is objectionable and will usually cause a defect in the weaving.

It is the general object of my invention to provide an improved construction of dobby linger by which such accumulations of lint and dirt will be reduced and largely eliminated.

It is desirable and customary to provide dobby fin-gers with a thickened lower peg-engaging edge portion, and it is a further object of my invention to provide animproved method of producing such a thickened edge portion.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claim.

Two forms of the invention are shown in the drawing in which e Fig. 1 is a sectional side elevation of parts of a dobby embodying my improvements;

Fig. 2 is an enlarged side elevation of one of my improved dobby lingers; e

Fig. 3 is a plan view thereof, looking in the direction of the arrow 3 in Fig. 2;

Fig. 4 is a Vsectional elevation, taken along the line 4 4 in Fig. 2;

Figs. 5 and 6 are sectional elevations, illustrating my improved method of forming the dobby finger shown in Figs. 2, 3 and 4;

Fig. '7 is a partial side elevation of a modified form of dobby linger; and

Fig. 8 is a sectional elevation, taken along the l line 8 8 in Fig. 7.

Referring to Fig. 1, I have shown a portion of a usual harness jack I0 pivotally connected to a dobby back lever Il, to which upper and lower dobby hooks I2 and I3 are pivoted at I4 and I5.

Dobby lingers 20 are mounted in closely parallel relation on a cross bar 2l and their outer ends are supported on a second cross bar 22 having spacing pins 23 for theends Vof the dobby lingers. Projecting end portions -24 of the fingers A2l) underlie'thelower Vhooks I 3Y or the lifter rods 25 for the Yupper hooks I2. Y

A pattern chain 26 is mounted on a pattern cylinder or roll 21 and the chain 26 is provided 5 with chain bars 28 having pegs 30 adapted to engage the Vlower edges of corresponding lingers 20 when in uppermost position, and adapted to t lift the lingers which are thus engaged.

All of the parts thus far described, with the exceptionof the fingers 20, are of the usual commercial construction and form no part of my invention.

Each linger 20, however, is of special construction and is provided with a large central recess or opening 32 and with a thickened lower edge portion 33 of substantial height.

The preferred method of forming the lingers is indicated inFigs. 5 and 6. The openings 32 are punched out at the same time that the 20 lingers 20 are punched from sheet steel plates or by a subsequent punching operation. Each finger 20 is then inverted, so that the portion 35 above the opening 32 will be at the bottom, as indicated in Fig. 5.V The linger is then placed over a rigid support or anvil 40, while a die or hammer' 42 is firmly pressed downward against the portion of the linger supported above the anvil. This part of the linger is thus transformed to the thickened portion 33, as indicated in Fig. 30 6, and is preferably provided with the usual concave lower Vedge portion 31 for centering the pegs 30.

The thickened edge portion 33 is preferably about equal in length to the opening 32 and the 3 relatively thin portion 35 is preferably about equal in height to the opening 32. n

I thus not only provide an improved and effective method of thickening and shaping the lower edge portion 33 of the dobby linger 20, but the large central opening 32 in itself also possesses the very desirable function of largely preventing such accumulation of lint and Vdirt as has previously caused defective operation.

It will be noted by reference to Fig. 1 that when the lingers 20 are in normal position, the openings V32 will be aligned so that a continuous passage of substantial cross section is provided from one end to the other of the series of dobby lingers.,k Lint and dirt entering between the portions 35 readily falls into the transverse passage formed by the. openings 32, from whichA passage it willY commonly clear itself or from which it may be quickly and easily removed manually.

Accumulation of lint and dirt between the closely adjacent thickened portions 33 is thus substantially eliminated, and the very objectionable lifting of non-indicated fingers by friction is avoided.

The thickened portions 33 are preferably of such height that the part 33 of a raised finger will not clear the part 33 of a lowered adjacent finger, thereby avoiding lockingiof -the fingers in raised position. Y

In Figs. 7 and 8 I have shown a dobby linger 50 having openings 5| as previously described, but having the thickened lower edgeiportion-'52 rformed by twisting the part of thefinger 50 below the opening 5| ninety degreesgt-insteadiof upsetting the edge portion-as inthe .form previously described. This form of my invention is preferably produced by acombinedtwistingtand press operation so that a concave lower'` surface 54 may be provided for the pattern pegs. In

.this construction, .the thickening of the lower vedge portionf'is :substantiallyA increased over .the

form shown in Fig. 4,fand atthensametimeithe @wider upper-edge portion and having a relatively large central opening through said finger in said "thinnerupper edge;portion, said central opening .being substantiallyqual in length to said thickene'dlower edge portion and bounded on one side "It'hereby :andcbeingasubstantially equal in height to one-half of said thinner upper edge portion, and saidopening substantially reducing friction .betweenadjaeerztudebbyfingers.Y q

,ELBRIBGE mfHoLME's. 

